Touch-sensitive devices may detect touch via several different mechanisms, including but not limited to optical, resistive, and capacitive mechanisms. In many devices utilizing a touch-sensitive input, it may be useful to determine the orientation of a finger, for example, to determine an orientation for displaying text or images on the device, to distinguish between users of a multi-user device, and/or to allow a user to control rotation of an image on a touch-sensitive display by rotating a finger over the image.
Various methods may be used for determining an orientation of a finger on a touch-sensitive device. For example, one approach involves attempting to match an image of a body of a finger pointing away from a fingertip utilizing a template algorithm to look for a match to a theoretical finger. However, such an approach may be difficult to implement, and may lead to incorrect results as well as sudden changes in determined orientation where errors in template matching occur.